ffi: update modsupport.rs for Python 3.13 (#4420)

newsfragments/4420.fixed.md

@@ -0,0 +1 @@
+Correct FFI definition `PyArg_ParseTupleAndKeywords` to take `*const *const c_char` instead of `*mut *mut c_char` on Python 3.13 and up.

newsfragments/4420.removed.md

@@ -0,0 +1 @@
+Remove FFI definition of private variable `_Py_PackageContext`.

pyo3-ffi/src/modsupport.rs

@@ -14,9 +14,14 @@ extern "C" {
  arg1: *mut PyObject,
  arg2: *mut PyObject,
  arg3: *const c_char,
- arg4: *mut *mut c_char,
+ #[cfg(not(Py_3_13))] arg4: *mut *mut c_char,
+ #[cfg(Py_3_13)] arg4: *const *const c_char,
  ...
  ) -> c_int;
+
+ // skipped PyArg_VaParse
+ // skipped PyArg_VaParseTupleAndKeywords
+
  pub fn PyArg_ValidateKeywordArguments(arg1: *mut PyObject) -> c_int;
  #[cfg_attr(PyPy, link_name = "PyPyArg_UnpackTuple")]
  pub fn PyArg_UnpackTuple(
@@ -26,32 +31,10 @@ extern "C" {
  arg4: Py_ssize_t,
  ...
  ) -> c_int;
+
  #[cfg_attr(PyPy, link_name = "PyPy_BuildValue")]
  pub fn Py_BuildValue(arg1: *const c_char, ...) -> *mut PyObject;
- // #[cfg_attr(PyPy, link_name = "_PyPy_BuildValue_SizeT")]
- //pub fn _Py_BuildValue_SizeT(arg1: *const c_char, ...)
- // -> *mut PyObject;
- // #[cfg_attr(PyPy, link_name = "PyPy_VaBuildValue")]
-
- // skipped non-limited _PyArg_UnpackStack
- // skipped non-limited _PyArg_NoKeywords
- // skipped non-limited _PyArg_NoKwnames
- // skipped non-limited _PyArg_NoPositional
- // skipped non-limited _PyArg_BadArgument
- // skipped non-limited _PyArg_CheckPositional
-
- //pub fn Py_VaBuildValue(arg1: *const c_char, arg2: va_list)
- // -> *mut PyObject;
-
- // skipped non-limited _Py_VaBuildStack
- // skipped non-limited _PyArg_Parser
-
- // skipped non-limited _PyArg_ParseTupleAndKeywordsFast
- // skipped non-limited _PyArg_ParseStack
- // skipped non-limited _PyArg_ParseStackAndKeywords
- // skipped non-limited _PyArg_VaParseTupleAndKeywordsFast
- // skipped non-limited _PyArg_UnpackKeywords
- // skipped non-limited _PyArg_Fini
+ // skipped Py_VaBuildValue
 
  #[cfg(Py_3_10)]
  #[cfg_attr(PyPy, link_name = "PyPyModule_AddObjectRef")]
@@ -159,9 +142,3 @@ pub unsafe fn PyModule_FromDefAndSpec(def: *mut PyModuleDef, spec: *mut PyObject
  },
  )
 }
-
-#[cfg(not(Py_LIMITED_API))]
-#[cfg_attr(windows, link(name = "pythonXY"))]
-extern "C" {
- pub static mut _Py_PackageContext: *const c_char;
-}

tests/test_pyfunction.rs

@@ -363,8 +363,7 @@ fn test_pycfunction_new() {
 #[test]
 fn test_pycfunction_new_with_keywords() {
  use pyo3::ffi;
- use std::ffi::CString;
- use std::os::raw::{c_char, c_long};
+ use std::os::raw::c_long;
  use std::ptr;
 
  Python::with_gil(|py| {
@@ -375,28 +374,38 @@ fn test_pycfunction_new_with_keywords() {
  ) -> *mut ffi::PyObject {
  let mut foo: c_long = 0;
  let mut bar: c_long = 0;
- let foo_ptr: *mut c_long = &mut foo;
- let bar_ptr: *mut c_long = &mut bar;
 
- let foo_name = CString::new("foo").unwrap();
- let foo_name_raw: *mut c_char = foo_name.into_raw();
- let kw_bar_name = CString::new("kw_bar").unwrap();
- let kw_bar_name_raw: *mut c_char = kw_bar_name.into_raw();
+ #[cfg(not(Py_3_13))]
+ let foo_name = std::ffi::CString::new("foo").unwrap();
+ #[cfg(not(Py_3_13))]
+ let kw_bar_name = std::ffi::CString::new("kw_bar").unwrap();
+ #[cfg(not(Py_3_13))]
+ let mut args_names = [foo_name.into_raw(), kw_bar_name.into_raw(), ptr::null_mut()];
 
- let mut arglist = vec![foo_name_raw, kw_bar_name_raw, ptr::null_mut()];
- let arglist_ptr: *mut *mut c_char = arglist.as_mut_ptr();
-
- let arg_pattern: *const c_char = CString::new("l|l").unwrap().into_raw();
+ #[cfg(Py_3_13)]
+ let args_names = [
+ c_str!("foo").as_ptr(),
+ c_str!("kw_bar").as_ptr(),
+ ptr::null_mut(),
+ ];
 
  ffi::PyArg_ParseTupleAndKeywords(
  args,
  kwds,
- arg_pattern,
- arglist_ptr,
- foo_ptr,
- bar_ptr,
+ c_str!("l|l").as_ptr(),
+ #[cfg(Py_3_13)]
+ args_names.as_ptr(),
+ #[cfg(not(Py_3_13))]
+ args_names.as_mut_ptr(),
+ &mut foo,
+ &mut bar,
  );
 
+ #[cfg(not(Py_3_13))]
+ drop(std::ffi::CString::from_raw(args_names[0]));
+ #[cfg(not(Py_3_13))]
+ drop(std::ffi::CString::from_raw(args_names[1]));
+
  ffi::PyLong_FromLong(foo * bar)
  }